The central object is HostSystem. Each property of HostSystem is a data object that encapsulates some information about the host. For example, the capability property is a HostCapability object, the runtime property is a HostRuntimeInfo object. See the API Reference for a list of the properties and the corresponding data objects.HostSystem methods allow you to perform certain tasks on ESX/ESXi hosts. However, many tasks are not performed through HostSystem methods, but through methods in managed objects related to HostSystem. For example, you manage the host time using the HostDateTimeSystem and you manage kernel modules using HostKernelModuleSystem.